The invention pertains to image acquisition and, more particularly, to image acquisition devices that can be manually adjusted and that are sealed to the elements, e.g., water, chemicals, dirt, dust.
Image acquisition refers to the capture of still or video images. It forms a basis for “machine vision,” i.e., the computer processing of images, and is used in manufacturing and industry for robotic assembly, parts inspection, quality control, etc. It is also increasingly used in military and security, as well as commercial and residential, applications.
Image acquisition devices, or “cameras” as they are commonly called, optimally utilize adjustable focus lenses. These have an advantage over fixed-focus lenses in that they permit optics (e.g., lens “glass”) to be set at optimal focal points for objects at varying distances, thus insuring sharpness of both close (or far) objects.
In traditional industrial and manufacturing image acquisition applications, cameras are used indoors (e.g., on factory floors) in controlled environments. As the range of image acquisition applications broadens, there is increasing need for cameras that can be used outdoors or in other less controlled situations, e.g., where there is dust, dirt, water, chemicals, and so forth.
To this end, ruggedized cameras are often protected from the environment by a protective cover and/or an enclosure. However, in order for an operator (e.g., plant worker, military/security personnel, home owner, etc.) to focus the cameras, the protective covers must be removed. Not only is this inconvenient, but it runs the risk of exposing the lens to potentially harmful factors. Moreover, such adjustment often requires the use of particular tools, which can be expensive and complicated to use.
Image acquisition devices with adjustable focus lenses routinely use motorized focus mechanisms and/or external locking features. The drawbacks of the former are that the motorized mechanisms are more complicated, expensive, and prone to failure, e.g., due to power loss, breakage, and so on. The drawbacks of the latter are that if an operator fails to set or release a lock, focussing may be substantially impaired. Moreover, setting and releasing the locks adds an additional step to operations.
An object of the invention is to provide improved image acquisition devices and methods.
A further object of the invention is provide such devices and methods as operate in rugged environments without exposing the lens.
A still further object of the invention is to provide such devices and methods as provide for focusing of the lens, e.g., without motorized mechanisms and/or the use of tools.
A still further object of the invention provide such devices and methods for locking of focus positions with improved focal accuracy and speed.
A still yet further objects of the invention provide such devices and methods as can be produced at low cost.